Chromium specific changes based onnative-client sdk release notes :
Added Compositor interfaces ( since Pepper 37 )
Compilation speed improvements due to validation caching of the translator and linker ( since Pepper 38 )
Performance improvement of SIMD vector shuffle ( since Pepper 38 )
postMessageAndAwaitResponse is now stable and allows JavaScript to communicate synchronously with NaCl embeds ( since Pepper 39 )
PNaCl is now based on LLVM 3.5 ( since Pepper 41 )
The x86 NaCl validators accept instructions from the AVX1 extensions ( since Pepper 41 )
The x86 NaCl validators accept instructions from the FMA3 extensions, as well as AVX2 instructions ( except VGATHER )
The SDK now contains experimental versions of i686-nacl-clang, x86_64-nacl-clang, and arm-nacl-clang as well as the clang++ equivalents. These toolchains are based on the same LLVM version as PNaCl, but can be used to generate NaCl .nexe files instead of translating a .pexe locally or using the GCC toolchain